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The Benefits of Natural Thermal and Acoustic Insulation

Acara Concepts specialises in distributing ecological and sustainable thermal and acoustic insulation materials.  The use of natural insulation in our homes and buildings is very beneficial to us in terms of our health, the saving of heat energy, the preservation of our buildings and the reduction in carbon dioxide emissions both during the manufacture and lifetime of the insulation.

Hofatex Wood Fibre thermal insulation is made from renewable and sustainable softwood timber off-cuts and so is safe to handle and it does not contain any harmful chemicals. Very importantly wood fibre is breathable which means that it can absorb and des orb water vapour from within the building without any damage to the product itself or the building structure. This water vapour will evaporate either externally or internally depending on weather conditions. Synthetic fibres cannot deal with moisture in the same way because the insulation stays wet and wet insulation allows much more heat to pass through it.

A 10% increase in moisture levels decreases U-values by 30%. Hofatex wood fibre retains its shape throughout its lifetime due to its high density and will not sag even if holding moisture, and so is very durable and reliable.

Because wood fibre insulation is the densest of all insulation materials it stores excess heat during the warm summer days by up to 12 hours and then gradually releases this heat during the night as it cools. This is particularly critical in timber frame homes and in converted attic spaces as these tend to overheat - think of caravans in summer!  The density of the wood fibre also means that it will add considerable sound insulation to the property.  

The PhoneStar board gives a very significant 36 decibels (dB) of airborne sound insulation before it is added on to any structure and it reduces impact sound by 21dB when placed on top of the industry standard concrete test floor.  It also significantly reduces noise through timber floors.

Soundproofing Walls and Ceilings

There are various options for soundproofing walls and ceilings with PhoneStar depending on the space available and the severity of the noise.  The walls and ceilings can be timber frame or masonry.  It is strongly recommended to decouple the PhoneStar sound insulation board from the wall or ceiling and this is done by fitting 16mm deep metal resilient bars onto the wall or ceiling first and then screwing the 15mm thick PhoneStar boards onto these bars only.  The resilient bars act a little like shock absorbers and also provide a cavity space which breaks the sound bridge which would otherwise be created by noise travelling through the wall or ceiling and directly into the PhoneStar board.  This will give a much improved result compared to simply attaching the PhoneStar boards directly to the structure.  The optimum result is achieved when the resilient bars are first mounted onto timber stud battens with high density flexible insulation in between the battens and this system should reduce airborne noise by about 85%.

Soundproofing Floors

It is very easy to soundproof a floor with PhoneStar.  The 15mm thick PhoneStar boards are simply laid floating on top of floorboards or a concrete floor and then any floor covering can be laid over them.  This will reduce both airborne noise and impact or footstep noise by about 50%.  However if you are undertaking a new-build or extension project it is strongly advised to also fit 16mm deep resilient bars to the underside of the timber joists or concrete ceiling downstairs before fitting the acoustic plasterboard. This decoupling downstairs will mean that both airborne and impact sound should be reduced by about 85%.

Please see our website for more helpful advice:

PhoneStar Sound Insulation is a very high performing soundproofing board that significantly reduces both airborne sound (e.g. music or TV noise) as well as impact sound (e.g. footstep noise heard overhead).  The 15mm thick PhoneStar board can be used on walls, floors and ceilings – both timber and masonry - so is very versatile, and it is also made of natural, breathable materials.

Killossory, Kilsallaghan, Swords, Co. Dublin

Tel: +353 (0)1 8409 286, Fax: +353 (0)1 6877 075, Mobile: +353 (0)87 2844 768


The main properties of PhoneStar are that it is heavy, it is dense but it also has a soft filling consisting of very fine quartz sand.  These are the three attributes required to stop noise such as noise between neighbouring properties or noise within one’s own home.  Many soundproofing quilt materials are soft but are not dense or heavy and so will not reduce much sound.  Other products are heavy and dense but they are not soft so tend to vibrate a lot.  

Therefore cold air will not just whip through the insulation as it would with lightweight man-made insulation. So when all the benefits of Hofatex wood fibre insulation are considered including its thermal performance, acoustic performance, longevity, thermal mass, vapour openness, ease of use, wind-tightness and probably most importantly its health benefits due to no harmful chemicals being emitted into the property, this insulation becomes very advantageous and price competitive when compared to synthetic fibres and plastic insulation materials.

All of the wood fibre sarking boards that go on external walls and roofs have tongue and groove joints and this coupled with their high density means that building envelopes will be wind-tight.